[Late Ming treatises on Chinese and Islamic calendrical systems as seen in the Seki Teisyo]

The Seki Teisyo (see text for symbol), a manuscript compiled by Seki Takakazu (see text for symbol)) in 1686, is known to consist of 15 treatises which Seki extracted from an early Qing astronomical and astrological corpus, the Tianwen Dacheng Guankui Jiyao (see text for symbol). Containing a detailed account of the Shoushi Li (see text for symbol) as well as a comparative study of Chinese and Islamic calendrical systems, these treatises have drawn the attention not only of Seki but of modern historians. In this paper, I show that 14 of the 15 treatises Seki selected had been composed by a late Ming scholar, Zhou Shuxue (see text for symbol), who discussed issues with Tang Shunzhi (see text for symbol). Their time predates the era in which the mathematical basis of the Shoushi Li was scrutinized and a new Chinese calendrical system was invented incorporating Western astronomical knowledge. I also mention some earlier works that Tang and Zhou could have consulted. Although Seki never knew the author of the treatises nor their background, his concern centered on themes that seem to have derived from one of those earlier works: the Liyuan(see text for symbol).